<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>

    <script>


        var sum3 = function(a,b) {
            c = a+b;
            return a+c
        }


        var sum3 = (a,b) => {
            c = a+b
            return a+c
        }
        console.log(sum3(1,2));


    </script>

</body>
</html>